I went for a longer ride on my 800Li today for fun, generally taking it easy on both my legs and the accelerator. I used 3/4 of the battery capacity (16 AH) in 34 miles of bike path, road, hills, dirt road, and single track, pedaling lightly all the time. The advertised 30 mile range is easily attainable - just not at constant full throttle in the city.

By the way, Optibike's bottom bracket incorporates a brushless motor, reduction gearing, cooling system, freewheel, bearings, and spindle. It is the logical extension of taking the sort of motor bdcain is so excited about (though one with about half the power) and developing it into a worthy drive system, including safety, reliability, and usability enhancements.